An engine disposed in a vehicle is anchored to a body of the vehicle through an engine-mounting bracket. The engine-mounting bracket suppresses vibration from the engine. As a result, such vibration is intercepted and prevented from being transmitted to the vehicle body or, e.g., to the interior of the vehicle.
An engine-mounting bracket is disclosed in published Japanese Patent Application Laid-Open No. 1-202525. An automobile engine-supporting device, which is disclosed in this publication, has a supporting bracket and a retaining bracket secured to one another by means of a fastening bolt. The supporting bracket supports a support member which is provided on the engine. The retaining bracket is mounted on the vehicle body. In such an automobile engine-supporting structure, a cutout portion is formed at either a bolt insertion-hole of the supporting bracket or a bolt insertion-hole of the retaining bracket for permitting the engine to be turned on an axis extending in a transverse direction of the vehicle in proportion with impact loads. The impact loads are imposed on the engine upon a collision of the vehicle. As a result, the engine is prevented from horizontal movement in a rearward direction of the vehicle upon a frontal collision of the automobile.
In conventional engine-mounting brackets, an engine-mounting bracket 102, as shown in FIGS. 13 and 14, includes first and second brackets 104A and 104B in which the second bracket 104B is attached to either the engine or the vehicle body, while the first bracket 104A is fitted to the second bracket 104B. The first bracket 104A is formed by a plate-shaped member being bent into a U-shaped configuration in cross-section. The second bracket 104B is formed by way of casting.
In addition, a sleeve 114 is fixed to the first bracket 104A between supporting arm portions 106 by means of a fixing bolt 108. Further, a bush 110 is fixed onto the periphery of the sleeve 114. The bush 110 is attached to the other of the engine and the vehicle body. The supporting arm portions 106 are formed with hole portions 152 for inserting the fixing bolt therethrough.
When desired, the second bracket 104B and the bush 110 may alternately be secured to the engine and the vehicle body.
Since the first bracket 104A is formed by the plate-shaped member being bent into a U-shape in cross-section, the engine-mounting bracket 102 becomes difficult to manufacture. Further, in producing a large number of components, these difficulties lead to increased costs which are disadvantageous from an economical viewpoint.
Additionally, as the supporting arm portions 106 are formed with the hole portions 152, through which the fixing bolt is inserted when the bush and the sleeve are fixed to the bracket, there further arises the inconvenience of the required hole-matching practice, which results in further inconvenience during the assembly process.
In order to avoid the aforesaid inconveniences, the first bracket 104A may be cast of a metallic material such as iron or aluminum. Alternatively, the first and second brackets 104A and 104B may be integrally molded by way of casting.
However, as shown in FIGS. 15 and 16, when a bracket 204 is integrally cast-molded, drafts or tapers are formed at supporting arm portions 206 of the bracket 204, as illustrated in FIGS. 17 and 18. As a result of being formed with the drafts, the supporting arm portions 206 must be machined to remove the drafts so as to provide abutment surfaces against which a fixing bolt 208, a nut 220, and a sleeve 214 are pressed. This causes yet further inconveniences of an additional machining process, difficulties in manufacturing, and increased costs which are disadvantageous from an economical viewpoint.
Further, as illustrated in FIGS. 19 and 20, even when inner and outer sides of the supporting arm portions 206 are formed with respective abutment surfaces 262a and 262b, distance 206Sa between the inner surfaces of the supporting arm portions 206 must be greater than length 214S of the sleeve 214 by a slight amount (i.e. some 2 millimeters). However, when the bush 210 and the sleeve 214 are assembled onto the bracket 204 at the supporting arm portions 206, deflection caused by a difference between the aforesaid distance 206Sa and length 214S is brought about by the tightening force of the fixing bolt 208 and/or that of the nut 220. Such deflection causes stresses which are then exerted on the supporting arm portions 206.
As a result, the integrally cast-molded brackets have inconveniences in that: the supporting arm portions are deficient in flexibility when compared with those formed by sheet metal, which is thus disadvantageous in view of practical use; and, it is difficult to realize the brackets by way of casting.
To overcome or minimize the above-mentioned inconveniences, the present invention provides an engine-mounting bracket disposed between an engine and a vehicle body, comprising a bracket attached to one of the engine and the vehicle body, and a bush fitted to the other thereof, the bush being fixed to the bracket between supporting arm portions of the bracket by means of a fixing bolt, wherein the bracket has cutout portions defined at the supporting arm portions for fixing the bush to bracket.
According to the invention having the above structure, when the bracket and the bush are assembled together, the bush is brought into engagement with the cutout portions that are formed at the supporting arm portions of the bracket. The bush is then fixedly positioned between the supporting arm portions by means of the fixing bolt. As a result, the cutout portions present at the supporting arm portions obviate the need for conventional hole-matching practice, and consequently enhance convenience of assembly. Further, the castability of the engine-mounting bracket provides fewer components and reduced costs.